Thanks, I got the first one as a big omnibus at 1,000 pages and I love it. It is better than the TV series and moves at a much faster pace and even though it's the same characters they are all in different 'orders' and it is different to the TV series. I'm really enjoying it.
I googled the graphic novels- they are more shocking and violent than the series imo. I'm glad I looked as ds was trying to persuade me he was old enough to read them as I won't let him watch the series